True, we had several discussions on this subject....Basically, it's the matter of personal taste..
Are you planning on using slot-2 expansions, do you already have a working NDS.....

Think about it and see in what are you interested, if you want new features that DSi offers, wait for the US/european release and buy it, but if you won't be using cameras, and music player, you may stick with your current DS/get the Lite!